An agricultural combine generally includes a threshing system including at least one concave disposed about a threshing rotor of the system. A gap will be located between the concave and rotor, and is desirably variable for accommodating different crops and conditions. In particular, it has become a desirable feature to have a capability to remotely adjust the gap just before and during operation of the combine. To meet this desire, concave adjust assemblies or mechanisms have been developed to allow concave gap adjustments to be made by the combine operator or another person using a suitable input device or switch, located in the operator cabin or another location, and some systems allow the adjustments to be made automatically. Such adjust assemblies or mechanisms typically include a motor in driven relation to a gear train in connection with the concave, operation of which can be used for precisely adjusting or setting the concave gap.
A problem that has been discovered with use of such remote concave adjust assemblies, however, is that threshing forces generated by the rotation of the rotor and resulting impacts with the crop material during threshing, can be transmitted through the concave and the apparatus in support thereof, e.g., linkages, cross bar, etc., to elements of the concave adjust assembly, resulting in breakage and/or failure thereof. It has been found that the threshing forces, particularly those resulting from intermittently occurring plugs or slugs of crop material, can translate into repeating impulse or shock loads which have a jack hammering effect on the adjust assembly elements of the adjust assembly which can cause fatigue failures over time.
What is sought therefore, is an apparatus for a concave adjust assembly, which provides the desired concave adjustability, and which overcomes one or more of the problems set forth above.